Remove the workspace entry for find_protobuf_cmake

Using a workspace to identify these files isn't terribly useful,
because there isn't great cause for allowing Drake downstreams to
replace them with a different copy.  Using new_local_repository
is a bit tricky to get right so we are trying to avoid it, thus
its worth just dropping this down to package-level dependencies
instead of a workspace.

WORKSPACE

@@ -55,12 +55,6 @@ local_repository(
     path = "third_party/com_github_google_protobuf",
 )
 
-new_local_repository(
-    name = "find_protobuf_cmake",
-    build_file = "@drake//tools/workspace/protobuf:package.BUILD.bazel",
-    path = __workspace_dir__ + "/third_party/com_kitware_gitlab_cmake_cmake",
-)
-
 load("//tools/workspace/ibex:package.bzl", "ibex_repository")
 
 ibex_repository(name = "ibex")

third_party/BUILD.bazel

@@ -24,4 +24,9 @@ exports_files(
     visibility = ["@libbot//:__pkg__"],
 )
 
+exports_files(
+    glob(["com_kitware_gitlab_cmake_cmake/**"]),
+    visibility = ["//tools/workspace/find_protobuf_cmake:__pkg__"],
+)
+
 add_lint_tests()

tools/install/install.bzl

@@ -529,7 +529,7 @@ install_files = rule(
         "rename": attr.string_dict(),
         "strip_prefix": attr.string_list(),
         "workspace": attr.string(),
-        "allowed_externals": attr.string_list(),
+        "allowed_externals": attr.label_list(allow_files = True),
     },
     implementation = _install_files_impl,
 )

tools/workspace/BUILD.bazel

@@ -20,7 +20,6 @@ _DRAKE_EXTERNAL_PACKAGE_INSTALLS = ["@%s//:install" % p for p in [
     "drake_visualizer",
     "eigen",
     "fcl",
-    "find_protobuf_cmake",
     "fmt",
     "ignition_math",
     "ignition_rndf",
@@ -39,6 +38,7 @@ _DRAKE_EXTERNAL_PACKAGE_INSTALLS = ["@%s//:install" % p for p in [
     "vtk",
 ]] + ["//tools/workspace/%s:install" % p for p in [
     "net_sf_jchart2d",
+    "find_protobuf_cmake",
     "optitrack_driver",
 ]] + select({
     "//tools:with_gurobi": ["@gurobi//:install"],

tools/workspace/find_protobuf_cmake/BUILD.bazel

@@ -0,0 +1,27 @@
+# -*- python -*-
+
+load(
+    "@drake//tools/install:install.bzl",
+    "install_files",
+)
+
+package(default_visibility = ["//visibility:public"])
+
+install_files(
+    name = "install",
+    dest = "lib/cmake/drake/modules",
+    files = [
+        "//third_party:com_kitware_gitlab_cmake_cmake/3.10/Copyright.txt",
+        "//third_party:com_kitware_gitlab_cmake_cmake/3.10/Modules/FindProtobuf.cmake",
+    ],
+    allowed_externals = [
+        "//third_party:com_kitware_gitlab_cmake_cmake/3.10/Copyright.txt",
+    ],
+    strip_prefix = [
+        # The first strip_prefix match wins; thus, we will end up with:
+        # - install to "lib/cmake/drake/modules/FindProtobuf.cmake"
+        "com_kitware_gitlab_cmake_cmake/3.10/Modules",
+        # - install to "lib/cmake/drake/modules/3.10/Copyright.txt"
+        "com_kitware_gitlab_cmake_cmake",
+    ],
+)